Magnetic-head supporting mechanism

ABSTRACT

A magnetic-disc apparatus for recording or reproducing information in which a slider loading a magnetic-head is supported on a magnetic disc. A supporting mechanism for supporting the slider on the magnetic-disc includes a first supporting member mounting the slider and a second supporting member connected with the first supporting member. The first supporting member includes a mounting portion for mounting the slider, at least one flexible finger portion provided at opposite sides of the mounting portion and a connecting portion connected to the second supporting member. The second supporting member including at a tip portion, a constricted portion extended to an end direction having a narrow width than that between inner side edges of the two flexible finger portions and a projecting portion projecting from the constricted portion to the direction of width. The projecting portion is overlapped with the flexible finger portion in the outward direction of surface.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a magnetic-head supportingmechanism for a magnetic-disc apparatus, and in particular, to amagnetic-head supporting mechanism that is excellent in impactresistance.

[0003] 2. Description of the Related Art

[0004] It has been reported that when a large impact is applied to aconventional magnetic-disc apparatus in the direction perpendicular to adisc surface, a slider jumps up from the magnetic disc surface, istilted while floating, and falls from the angle of a slider floatingrail to contact and damage the disc surface (IEEE TRANSACTION ONMAGNETICS Vol. 31, No. 6, pp. 3006 to 3008: NOVEMBER, 1995). Thisarticle also reports that a “jump stop” is effectively provided on theslider in order to reduce the damage to the disc caused by an impact.

[0005] In addition, JP-A-8-102159 discloses a mechanism comprising a pinprotrusion (a limiter section) on a cover or on a base of amagnetic-disc apparatus wherein if the magnetic-disc apparatus issubjected to an impact to oscillate a suspension having a magnetic headat its free end, the free end of the suspension contacts the pinprotrusion and is stopped from being further displaced toward the baseor cover.

[0006] According to the conventional mechanism, if the slider issubjected to an impact and leaves the disc surface, the jump height isrestricted by the jump stop or pin protrusion to a predetermined valueor less. An object of this configuration is to reduce the speed oracceleration at which the slider collides against the disc in order toreduce the damage to the slider and disc upon the impact, therebyimproving the impact resistance of the magnetic-disc apparatus.

[0007] On the other hand, the degree of damage depends on the magnitudeof the speed and acceleration at which the slider contacts the disc aswell as the extent of the contact area. That is, the contact areasignificantly varies depending on whether a floating surface (a surfacethat is opposed to the disc surface and on which a floating force iseffected) of the slider contacts the disc surface in parallel or theslider rotates and contacts the disc surface at the corners of itsfloating surface or at its bleed surface (a surface that is opposed tothe disc surface and on which a floating force is not effected). Thus,even if the slider contacts the disc surface at the same speed andacceleration, the contact area pressure (stress) significantly variesdepending on the contact areas of the slider and disc surface, that is,the position of the slider in which it collides against the discsurface, resulting in significantly different degrees of damage. Theprior art does not take this point into account.

OBJECT AND SUMMARY OF THE INVENTION

[0008] In view of this point, it is an object of this invention thatwhen the magnetic-disc apparatus is subjected to a large impact to causethe slider to jump from the disc surface and the slider then re-contactsthe disc surface, the contacting position of the slider is controlled toprevent the contact area from being reduced in order to reduce contactdamage, thereby improving the impact resistance.

[0009] In other words, when the magnetic-disc apparatus is subjected toan impact to cause the slider to jump and the slider then re-contactsthe disc surface, the position (angle and state) of the slider iscontrolled to provide a sufficient contact area (prevent the contactarea from being reduced) in order to reduce the contact area pressure(stress), that is, damage.

[0010] It is another object of this invention to improve the impactresistance of the magnetic-disc apparatus and to provide a magnetic-headsupporting mechanism that allows the slider to be easily mounted on thesuspension and that has an excellent assembly capability.

[0011] To achieve these objects, the magnetic-head supporting mechanismaccording to this invention is composed of a slider on which a magnetichead is mounted; and a suspension that holds the slider and that pressesthe slider against the disc surface from the rear surface of the slider(the surface opposite to the disc-opposed surface), the suspensionconsisting of a gimbal (also referred to as a “flexure”) and a loadbeam.

[0012] The gimbal is composed of a mounting portion on which the slideris mounted (normally, joined with an adhesive); a stage portion thatconnects to one end of the mounting portion; two flexible fingerportions extending along the respective sides of the mounting portionfrom the other end of the stage portion; and a joint portion thatconnects to the other end of the flexible finger portions to join theload beam and that is joined with the tip of the load beam (normally bymeans of spot welding).

[0013] The gimbal has a low rigidity sufficient to avoid restraining themovement of the slider in the out-of-plane direction perpendicular tothe floating surface of the slider, (perpendicular to the floatingsurface) while having a high rigidity in the in-plane direction(parallel to the floating surface).

[0014] The load beam consists of an arm mounting portion, a springportion, and a flange portion, and the joint portion of the gimbal isjoined with the tip of the flange portion. On the other hand, the otherend of the flange portion connects to the spring portion, and the otherend of the spring portion connects to the arm mounting portion that ismounted on an arm portion that is very rigid. A load generated in thespring portion is transmitted through the flange portion, via a pivot (aprotrusion) provided at the tip of the flange portion to protrude in theslider direction, to the mounting portion of the gimbal mounted on therear surface of the slider. Since the mounting portion is joined withthe rear surface of the slider, the load transmitted to the mountingportion acts to press the slider. The load generated in the springportion is generated by bending the spring through a predetermined angleprior to installation in the magnetic-disc apparatus so that the springis installed approximately in parallel to the disc surface.

[0015] The slider is mounted on the load beam via the gimbal, asdescribed above, and is pivotally supported by the pivot, so it freelyrotates around the pivot in the out-of-plane direction perpendicular tothe floating surface.

[0016] The magnetic head supporting mechanism having the above mechanismhas a roof portion formed by extending the tip of the flange portion ofthe load beam to the rear surface of the slider. Specifically, if theroof portion is projected onto the gimbal, its size is slightly smallerthan or approximately equal to that of the gimbal. In addition, the roofportion is formed by integrally extending the flat portion of the flangeportion, and is normally prevented from contacting the flexible fingerportions and stage portion of the gimbal. That is, the roof portion doesnot restrain the movement of the slider.

[0017] According to this configuration, even when a large impact isapplied to the magnetic-disc apparatus to cause the slider to jump fromthe disc surface and to start rotating around the pivot through a largeangle, the gimbal, which rotates with the slider, contacts the roofportion to restrict the rotation of the slider. This enables theposition (state) of the slider in which it contacts the disc surfaceafter a jump to be controlled. Specifically, the substantial rotation ofthe slider causes the edges of the bleed surface of the slider (the fourcorners of the slider) or of the floating surface to contact the discsurface, thereby preventing the disc from being damaged due to a highcontact area pressure (stress) caused by a small contact area.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a general view of a magnetic-disc apparatus according tothis invention;

[0019]FIG. 2 is a magnetic-head supporting mechanism according to thisinvention;

[0020]FIG. 3A is a detailed view of a tip of the magnetic-headsupporting mechanism according to this invention;

[0021]FIG. 3B is a sectional view of a load beam in FIG. 3A taken alongline R-R;

[0022]FIG. 4 is a side view of the magnetic-head supporting mechanismaccording to this invention;

[0023]FIG. 5A is a top view of a roof portion of the load beam accordingto this invention;

[0024]FIG. 5B is a side view of a roof portion of the load beamaccording to this invention;

[0025]FIG. 6A is a top view of a gimbal shape according to thisinvention;

[0026]FIG. 6B is an enlarged view of a portion C in FIG. 6A;

[0027]FIG. 6C shows FIG. 6A as seen from direction DD;

[0028]FIG. 7A is a sectional view of FIG. 3 taken along line VII-VII;

[0029]FIG. 7B shows a maximum rotation state of FIG. 7A;

[0030]FIG. 8A shows a maximum pitch angle according to a firstembodiment;

[0031]FIG. 8B shows the maximum pitch angle of a conventionalmagnetic-head supporting mechanism;

[0032]FIG. 9A compares a contact area obtained when the angle of a bleedportion is 90° with a contact area obtained when the angle of the bleedportion is 45°;

[0033]FIG. 9B shows a state in which the angle of the bleed portion is90 or 45°;

[0034]FIG. 10A is a top view of a load beam according to a secondembodiment of this invention;

[0035]FIG. 10B is a bottom view of the load beam according to the secondembodiment of this invention;

[0036]FIG. 11 is a top view of a load beam according to a thirdembodiment of this invention;

[0037]FIG. 12A is a top view of a load beam according to a fourthembodiment of this invention;

[0038]FIG. 12B is a side view of the load beam according to the fourthembodiment of this invention;

[0039]FIG. 13A is a top view of a load beam according to a fifthembodiment of this invention;

[0040]FIG. 13B is a sectional view of FIG. 13A taken along line C-C;

[0041]FIG. 14A is a top view of a gimbal portion according to the fifthembodiment of this invention;

[0042]FIG. 14B is a side view of FIG. 14A;

[0043]FIG. 15A shows a general configuration of the fifth embodiment ofthis invention;

[0044]FIG. 15B is a sectional view of FIG. 15A taken along line D-D;

[0045]FIG. 15C is a sectional view of FIG. 15A taken along line D-D,showing a maximum rotation state;

[0046]FIG. 16 is a top view of a load beam according to a sixthembodiment of this invention;

[0047]FIG. 17 is a perspective view of a seventh embodiment of thisinvention;

[0048]FIG. 18 is a sectional view of FIG. 17 taken along line A-A;

[0049]FIG. 19 is a side view showing an eighth embodiment of thisinvention;

[0050]FIG. 20 is a bottom view of FIG. 19 (without slider);

[0051]FIG. 21 describes the effects of this invention;

[0052]FIG. 22A shows a configuration of a conventional magnetic-headsupporting mechanism;

[0053]FIG. 22B shows a load beam in FIG. 22A;

[0054]FIG. 23A is a sectional view of FIG. 22A taken along line B-B; and

[0055]FIG. 23B shows a maximum rotation state of FIG. 23A.

DESCRIPTION OF THE EMBODIMENTS

[0056] A first embodiment of this invention is described with referenceto FIGS. 1 to 9.

[0057]FIG. 1 shows a general view of a magnetic-disc apparatus in whicha magnetic-head supporting mechanism according to a first embodiment ofthis invention is mounted.

[0058] A magnetic discs 1 on which information is recorded is laminatedon a spindle 2. A magnetic head (not shown) used to record and reproduceinformation on and from the magnetic disc is mounted on a slider 4 of amagnetic-head supporting mechanism 5. The magnetic-head supportingmechanism 5 is joined with the arm 6. The magnetic head is placed at apredetermined radial position by a carriage 9 consisting of a pivotbearing 7 and a voice coil motor 8. These mechanisms are mounted in alunch-box-shaped base and are sealed by a cover (not shown). The presentmagnetic-head supporting mechanism improves impact resistance to enablerecording and reproduction at a high density even when the magnetic-discapparatus is configured as a portable type.

[0059]FIG. 2 shows the overall magnetic-head supporting mechanism 5according to the first embodiment. An arm mounting portion 10 connectsto a spring portion 11, which connects to a flange portion 12. Aconstricted portion 100 is provided at the tip of the flange portion 12,and a pivot 13 and a roof 14 are provided at the tip of the constrictedportion 100. The arm mounting portion 10, spring portion 11, and flangeportion 12, constricted portion 100, pivot 13, and roof 14 are composedof a single member and are collectively referred to as a “load beam 101”below. This invention is explained in conjunction with the pivotprovided at the tip of a flat portion 12 a of the flange portion 12 forconvenience. By bending the spring portion 11 through a predeterminedangle prior to installation in the apparatus and mounting itapproximately in parallel to the disc surface during installation, aplunge load on the slider 4 is generated by means of the flexure of thespring portion 11. The plunge load is transmitted through the flangeportion 12 via the pivot 13 to the slider 4. Instead of providing theconstricted portion 100, the tip side of the flat portion 12 a can becontinuously tapered where the pivot and roof can be provided. Theconfiguration and operation of the roof are described below.

[0060]FIG. 3A shows details of the tip of the magnetic-head supportingmechanism 5, and FIG. 3B shows the relationship between the flat portion12 a and a U-shaped bent portion 12 b in a cross section of the loadbeam 101 taken along line R-R. The constricted portion 100 is providedat the tip of the flat portion 12 a of the flange portion 12, and aportion of the flat portion 12 a that is closer to its tip than theconstricted portion has the pivot 13 and roof 14 thereon. In addition,the roof 14 has windows 16 used to admit ultraviolet rays and to allowthe slider mounting state to be observed. A gimbal 20 is provided underthe roof 14, and the slider 4 is mounted on the tip side of the gimbal20 by means of adhesion. The width of the roof 14 is larger than orapproximately equal to that of the gimbal 20, and its tip extendsapproximately as far as the tip of the gimbal 20.

[0061] In addition, as shown in FIG. 3, the windows 16 enable the rearsurface of the slider 4 to be directly observed. In the figure, thelateral sides 4 a (side edges) of the slider 4 can be observed throughthe widthwise centers of the windows 16 along the longitudinaldirection. Thus, when the roof 14 is provided on the gimbal 20, it canbe easily determined whether the slider 4 is mounted on the gimbal 20 ata predetermined angle. An ultraviolet-hardening adhesive can be used sothat the mounting portion used to mount the slider 4 on the gimbal 20 isdirectly irradiated with ultraviolet rays (UV) through the windows 16 toharden the adhesive, thereby reducing the time required for adhesion andproviding a predetermined adhesion strength. Light can enter a diagonaldirection, so the direct underside (slider side) of the pivot 13-sideedges of the windows 16 approximately aligns with the edges of themounting portion used to mount the slider 4 thereon. The shapes andsizes of the mounting portion and windows are described below.

[0062]FIG. 4 shows a side view of a magnetic head supporting mechanismaccording to a first embodiment. A pivot 13 is provided beyond theconstricted portion 100 located on the tip side of the flat portion 12 aof the flange portion 12. The gimbal 20 is mounted under the flatportion. The flange-side end surface of the gimbal 20 is welded to theflat portion 12 a, while the other end reaches the slider 4 via a stagedportion 23, with the slider mounted with an adhesive on the mountingportion 24 connecting to the staged portion. The top of the pivot 13applies a load to the slider via the mounting portion 24.

[0063]FIG. 5 shows details of the roof portion of the load beam 101according to the first embodiment. A sheet metal is etched to create theentire shape and windows, and the U-shaped bent portion of the flange 12b is molded by means of press working. The pivot 13, which is molded bymeans of press working, is located at the tip of the flat portion 12 a,and the roof 14 is formed that have the two windows 16 around the pivot.The roof 14 and pivot 13 are formed of the same sheet metal as in theflat portion 12 a.

[0064]FIG. 6 shows the shape of the gimbal used in this embodiment. Thegimbal 20 is composed of a joint portion 21 in order to join the loadbeam; two flexible finger portions 22; and a staged portion 23; and amounting portion 24 used to mount the slider 4. The flexible fingerportions 22 support the slider 4 without restraining the movement of theslider 4 in the direction perpendicular to the slider floating surface(out-of-plane direction). The staged portion 23 prevents the slider 4mounted on the mounting portion 24 from contacting the flexible fingerportions 22, and enables pivot supporting so that the slider 4 can movefreely. FIGS. 6B and 6C show an enlarged side view of a portion C and aprojection from plane D-D.

[0065] The effects of this invention are described with reference toFIGS. 7, 8, and 9.

[0066]FIG. 7A shows a cross section taken along line VII-VII in FIG. 3,and FIG. 7B shows the maximum rotation angle Θr of the slider 4 in aroll direction. The thickness of the gimbal depends on the size of theslider (precisely speaking, air film rigidity), the height of the pivotdepends on the stability of press working, and the thickness of the loadbeam is determined by the elastic modulus of the spring portion.According to this invention, even if the slider is rotated by anexternal impact, the tips of the flexible finger portions 22 contact theroof 14 to prevent the slider from rotating through a predeterminedangle or more, as shown in FIG. 7B.

[0067] As shown in FIG. 7A, the size of the roof may be slightly largerthan or equal to the size of the flexible finger portions. The rotationangle is affected by the gap between the roof 14 and the flexible fingerportions 22, and can be reduced by reducing this gap. Even when the roof14 is configured to be slightly smaller than the flexible fingerportions 22, a predetermined angle can be obtained by setting a smallergap.

[0068] Then, the maximum rotation angle ΘrMax in a roll direction is3.2° (arctan (0.045/0.8)) if, for example, the roof width is 1.6 mm andif the gap between the roof 14 and the flexible finger portions 22 is0.045 mm.

[0069] On the other hand, a conventional magnetic head supportingmechanism, which is shown in FIG. 22A, does not have a roof but only apivot 13 at the tip of the flange portion. Thus, nothing covers the topsurface of a flexible finger portion 22 of the gimbal. For more clarity,FIG. 22B shows only a conventional load beam. As is apparent from acomparison between FIG. 22B and FIG. 5 for the first embodiment, theconventional magnetic head supporting mechanism does not include theroof portion according to this invention. In addition, the width of theconventional pivot 13 mounting portion does not include the roofaccording to the first embodiment of this invention.

[0070]FIG. 23A shows a cross section taken along line B-B in FIG. 22A.This figure shows that there is nothing on the top surface (opposed tothe slider) of the flexible finger portion 22 that interferes with themovement of the portion 22, as described above. Thus, if the slider isrotated by an impact, the gimbal mounting portion 24 rotates until itcontacts the side edge of the pivot 13.

[0071] Thus, if, for example, the gap between the mounting portion 24and the side edge of the pivot is 0.089 mm and the width of the sideedge of the pivot is 0.72 mm, the maximum rotation angle of the sliderreaches 14° (arctan (0.089/0.36)). This is about four times as large asthe value of the roofed magnetic-head supporting mechanism (=14°/3.2°).

[0072]FIG. 9 shows the relationship between the angle and contact areameasured when the slider contacts the disc surface after rotatingthrough such a large angle. The horizontal axis indicates the rotationangle of the slider, while the vertical axis indicates the inverse ofthe contact area. This figure shows that as the angle value increases,the contact area decreases, that is, the contact area pressureincreases, resulting in severer damage to the disc surface.

[0073] In addition, as a condition for the above calculations, the angleof the bleed portion of the slider is set at 90° or this portion ischamfered at 45° (see FIG. 9B). When the contact area at a rotationangle of 14° is compared with the contact area at a rotation angles of3°, this value is much smaller at 3° (10% or less). This effect remainsunchanged if the discharge end of the slider is chamfered at 45° (theangle of the bleed portion is 135°).

[0074] This invention can reduce the rotation angle of the slider downto 3° compared to 14° in the prior art, thereby reducing the damage tothe disc surface down to one-tenths or less.

[0075]FIGS. 8A and B show a comparison of the maximum pitch angle of thetip of the gimbal according to the first embodiment (Θp=7°=arctan(0.06/0.5)) with a conventional maximum pitch angle (Θp=15°=arctan(0.10/0.38)). In the first embodiment, even when the slider rotates in apitch direction (forward inclination), the tip of the flexible fingerportion 22 contacts the roof 14 to limit the rotation to a small range.The contact angle during rotation is 7° (=arctan (0.06/0.5)) if, forexample, the length from the pivot to the tip of the roof is 0.5 mm andif the gap between the roof and the flexible finger portion 22 is 0.06mm. Thus, the slider does not rotate through 7° or more.

[0076] According to this embodiment, the tip of the roof extendsapproximately as far as the tip of the flexible finger portion 23. Ifthe tip of the roof is extended beyond the tip of the flexible fingerportion, for example, to behind the magnetic head of the slider, themaximum pitch angle cannot be reduced and in fact, the weight of theload beam increases to reduce the natural frequency of the magnetic-headsupporting mechanism or the access speed.

[0077] In addition, if a signal line from the magnetic head provided atthe rear end of the slider is drawn in the direction perpendicular tothe floating surface, that is, in the direction of the load beam and ifthe roof is extended to behind the magnetic head of the slider, then theroof may interrupt the routing of the signal line. Thus, it is mostpreferable that the tip of the roof 14 extend approximately as far asthe flexible finger portion of the gimbal.

[0078] As shown in FIG. 8B, the conventional apparatus has no roof, sothe distance from the top of the pivot to the tip of the load beam isshort and the mounting portion 24 rotates until it contacts the tip ofthe load beam. The contact angle during rotation is 15° if, for example,the length from the pivot to the tip of the roof is 0.38 mm and if thegap between the roof and a mounting portion 24 is 0.1 mm. With sucharrangement the maximum rotation angle of pitch can be reduced to 46% ofthe conventional arrangement by providing the roof.

[0079] In addition, the above calculated angle varies with the height ofthe pivot and the shape of the gimbal or load beam, but the effects ofthe roof according to this invention remain unchanged.

[0080] As described above, in the first embodiment of this invention,the magnetic-head supporting mechanism includes the roof that controlsthe position of the slider. Thus, after a large impact is effected onthe disc apparatus to cause the slider to jump, the position of theslider can be controlled when it contacts the disc, thereby reducing thecontact area pressure between the slider and the disc. Thus, thisinvention can provide a magnetic-head supporting mechanism having a highimpact resistance and improve the impact resisting capability of themagnetic-disc apparatus in which the magnetic-head supporting mechanismis mounted. In addition, by providing an ultraviolet intake window usedto harden an adhesive and a window used to observe how the slider ismounted with the roof, the productivity of the magnetic head supportingmechanism can be improved.

[0081] A second embodiment of this invention is described with referenceto FIGS. 10A and 10B. This figure shows only the roof portion of thisembodiment in detail. The other sites are the same as in the firstembodiment, so they are omitted. The second embodiment differs from thefirst embodiment in that it has a rotation angle adjustment groove 40 inthe roof portion.

[0082] This groove is provided on the flexible finger portion of thegimbal to adjust the gap between the flexible finger portion and theroof. Specifically, according to the first embodiment, the gap betweenthe flexible finger portion 22 and the roof 14 is 0.045 mm and themaximum rotation angle is 3.2°, as shown in FIG. 7A. This gap can becontrolled to adjust the contact angle.

[0083] According to the first embodiment, the height of the pivot isused to control the gap. On the other hand, since the pivot is molded bypress working, its height and accuracy are limited. The secondembodiment includes a staged roof 17 having the rotating angleadjustment groove 40 in the gimbal-opposed surface of the roof accordingto the first embodiment.

[0084] The depth of the rotation angle adjustment groove 40 can bevaried to control the gap. This eliminates the need to control the gap(rotation angle) and requires only the height of the pivot to becontrolled, thereby increasing the degree of freedom. Furthermore, thedepth of the rotation angle adjustment groove can be accuratelycontrolled by means of machining or etching to accurately control themaximum rotation angle. For the impact-resisting magnetic-headsupporting mechanism to achieve stable floating, when no impact isapplied, the contact between the gimbal and the roof must be avoideddespite machining variation during the manufacturing of the pivot,whereas when an impact is applied, the slider must be stopped byminimizing the rotation angle.

[0085] This embodiment can meet this requirement because the staged roofcan be used to control the gap between the gimbal and the roof. Asdescribed above, this embodiment can control the rotation angle of theslider to improve the impact resistance as in the first embodiment, andcan also improve productivity using the ultraviolet incidence window andthe adhesion condition observation window.

[0086] A third embodiment of this invention is described with referenceto FIG. 11. This embodiment differs from the second embodiment in thatthe rotation angle adjustment groove 40 is staged by means of pressworking. Thus, the height of the staged roof is different from that ofthe windows as shown in FIG. 11. On the other hand, the rotation angleadjustment groove 40 is provided in the top surface of the flexiblefinger portion of the gimbal via a predetermined gap as in the secondembodiment. The staged roof with the rotation angle adjustment groove 40improves the degree of freedom in design for the height of the pivot,thickness of the gimbal, and the thickness and length of the load beam,as in the second embodiment. In addition, since the staged roof can bepress-worked simultaneously with the pivot 13, this embodiment providebetter productivity (mass productivity) than the second embodiment. Thisembodiment also provides high impact resistance and mass productivity asin the first embodiment.

[0087] A fourth embodiment of this invention is described with referenceto FIGS. 12A and 12B. This embodiment differs from the first embodimentin that it uses a four-point pressing roof 19.

[0088] The roof 19 has four protrusions, the tip of which corresponds tothe size (position) of one of the four corners of the roof 14 accordingto the first embodiment. The width 19 a of the four protrusions isapproximately the same as that of the gimbal. In addition, the tip ofthe protrusion extends approximately as far as the tip of the gimbal.Since only the four points of the gimbal are pressed, the ultravioletincidence window and adhesion condition observation window, which arerequired by the first embodiment, can be omitted to reduce the tareweight of the roof portion.

[0089] Thus, the impact resistance and productivity can be improved asin the first embodiment. Furthermore, the reduced weight of the roofportion precludes the natural frequency of the magnetic-head supportingmechanism from decreasing. This in turn enables the magnetic head to bepositioned promptly and accurately.

[0090] A fifth embodiment of this invention is described with referenceto FIGS. 13, 14, and 15. FIGS. 13A and 13B show details of a roofportion of a load beam according to the fifth embodiment. This inventiondiffers from the first embodiment in that a ring-shaped roof 30 isprovided at the tip of the flat portion of the flange portion.

[0091] The ring-shaped roof 30 is shaped like a donut and has a windowat its center. The pivot 13 is mounted at the tip of the flat portion asin the first embodiment, and the ring-shaped roof 30 extends from bothsides of the flat portion of the pivot 13 to form ring-shaped roof. FIG.13B also shows a cross section taken along the centerline C-C of theload beam. As shown in this cross section, the pivot 13 protrudes towardthe slider mounting portion as in the first embodiment. In addition, theroof tip 30 a is separated from the pivot 13 by a window 516.

[0092] In addition, the first embodiment includes the two windows 516along the sides of the slider, but the fifth embodiment has only one byincreasing the size of the window 516 above the width of the slider.Thus, as in the first embodiment, after the slider 4 has been mounted ona mounting portion 524 of the gimbal using an adhesive, ultraviolet rayscan be irradiated through the window 516 to allow the adhesive to behardened in a short time. Furthermore, when mounted on the mountingportion 524, the slider 4 can be supported from the load beam sidethrough the window 516. This feature allows the slider to be mountedeasily.

[0093]FIG. 14 shows the gimbal portion of the fifth embodiment. Itsbasic structure is the same as that of the gimbal configuration (FIG. 6)according to the first embodiment, and this gimbal is composed of aflexible finger portion 522; a staged portion 523; and a mountingportion 524. This differs from the gimbal according to the firstembodiment in that the flexible finger portion is shaped like a ringwith a curvature and in that a constricted portion 524 a is provided inthe mounting portion 524 of the slider. The ring shape of the flexiblefinger portion enables the further reduction of the effect of therestraint of the movement of the slider in the out-of-plane directionperpendicular to the floating surface of the slider. In addition, theslider is mounted on the mounting portion 524 so as not to be caught bythe constricted portion 524 a. Thus, the constricted portion 524 a workslike the flexible finger portion 522 to enable the slider to besupported without restraining its movement perpendicular to its floatingsurface (pitching, rolling, vertical movement).

[0094] In summary, as the miniaturization of the slider advances, itsair film rigidity decreases so the gimbal is required to support theslider without restraining its movement in the out-of-plane direction(perpendicular to the floating surface). Thus, the gimbal according tothis invention has the constricted portion 524 a to reduce the pitchingand rolling rigidity of the gimbal in order to support the slider withthe reduced restraint of its movement.

[0095]FIG. 15 shows a general view of the fifth embodiment. As shown inFIG. 15A, the ring-shaped roof 30 is formed to overlap the top surfaceof the flexible finger portion 522, and the roof tip 30 a is formed togenerally overlap two staged portion 523 provided at the tip of thegimbal. The roof tip 30 a, however, does not extend beyond the tip ofthe gimbal.

[0096]FIG. 15B shows a cross section taken along line D-D in FIG. 15A.The ring-shaped roof 30 has approximately the same width as the flexiblefinger portion 522 so as to cover its top surface. The slider mountingsurface 524 can be viewed through the window 516 in the ring-shaped roof30. As described above, the slider mounting surface 524 can beirradiated with ultraviolet rays through the window 516 to harden theadhesive between the slider and the mounting surface in a short time.The slider is mounted directly under the mounting portion 524, so it isnot shown. Of course, ultraviolet rays may be directly applied to theadhesive or may be diagonally incident as reflected (scattered) light.

[0097] The width of the window 516 is larger than that of the mountingportion 524 of the slider. Thus it is possible to support the mountingportion through the window 516 and it is easy to achieve the mountingportion through the window when the slider is mounted on the mountingportion.

[0098] The effects of this invention are described with reference to theexplanatory drawing in FIG. 15C. According to this embodiment, even ifan impact causes the slider to roll (lateral rotational movement), thering-shaped roof 30 provided on the flexible finger portion 522restrains the movement of the slider to prevent it from rotating througha large angle, as in the first embodiment. This feature in turn reducesthe contact area ratio shown in FIG. 9 and thus contact damage to thedisc.

[0099] In addition, with respect to the pitching movement (longitudinalrotational movement) of the slider caused by an impact, the roof tip 30a covers the tip of the gimbal, so the gimbal, which rotates with theslider, contacts the roof to hinder the slider from rotating through alarge angle in the pitching direction. This feature reduces the contactarea ratio and thus contact damage to the disc, as described above.

[0100] Since the mechanical rigidity of the roof is higher than that ofthe gimbal, the gimbal, which moves with the slider, can of course beprecluded from being deformed. Again, what is important in thisembodiment is that the tip of the roof does not extend beyond the tip ofthe gimbal and that the roof has approximately the same shape as thegimbal. This configuration minimizes the increase in the mass of theload beam due to the provision of the roof and reduces the rotation ofthe slider caused by an impact. If the roof is larger than the gimbal,the mass of the load beam increases to significantly increase thereduced mass of the head from the rotational center of the carriage,thereby reducing the data access speed.

[0101] In this case, the natural frequency and the positioning accuracyof the magnetic head also decrease. Furthermore, even if the roof islarger than the gimbal, its effects are still the same as those of aroof that is as large as the gimbal. This is because the rotation anglerestrained by the roof is not changed by setting the width of the rooflarger than that of the gimbal.

[0102] As described above, this embodiment provides effects similar tothose of the first embodiment. It also can provide an impact-resistingmagnetic-head supporting mechanism optimal for a slider of a small airfilm rigidity.

[0103]FIG. 16 shows a sixth embodiment of this invention. Thisembodiment differs from the fifth embodiment in that a window 31 isprovided in a roof 630. The window 31 serves to reduce the weight of theroof. This configuration can reduce the inertia moment of themagnetic-head supporting mechanism that uses the pivot bearing 7 of thecarriage 9 as a rotational center to enable fast seek operations.

[0104] If the external impact has a large value, the roof is deformedand cannot control the position of the slider. To solve this problem,the rigidity of the roof must be improved. Although the width orthickness of the roof can be increased to improve its static rigidity,doing this increases the tare weight of the roof and makes it tooflexible (a decrease in dynamic rigidity). In addition, the inertiamoment increases that uses the pivot bearing 7 as a rotational center.This embodiment provides the window 31 in the roof 630 to improve therigidity without increasing the mass of the roof 630. Consequently, theimpact resistance of the magnetic-head supporting mechanism can befurther improved.

[0105]FIGS. 17 and 18 show a seventh embodiment of this invention. Thisembodiment differs from the first embodiment in that the gimbal and theload beam are integrated together and that the pivot is omitted.

[0106] A slider 704 is mounted on a mounting portion 724, which connectsto a horizontal frame 725, and two flexible finger portions 722 extendfrom the respective sides of the horizontal frame to connect to a flangeportion 712. At a slider-side end of a flat portion 712 a of the flange,a roof 740 is provided over a rear surface 704 a of the slider. The roof740 is molded simultaneously with the press working of an L-shaped bentportion 712 b of the flange portion 712. FIG. 18 shows that the roof 740is provided over the rear surface 704 a of the slider. The roof 740 hasthe same effects as in the first embodiment and prevents the slider 704from rotating through a large angle due to an impact. That is, the roof740 restrains the rotation of the slider to reduce the contact anglebetween the slider and the disc. Thus, this embodiment can improveimpact resistance as in the first embodiment.

[0107] An eighth embodiment of this invention is described withreference to FIGS. 19, 20, and 21. In FIG. 20 the slider is not mounted.This embodiment differs from the seventh embodiment in that instead ofthe roof, a flange portion 812 is joined with a mounting portion 824using a FPC 50. The FPC 50 has a loop-like flexed portion 50 a so as notto hinder the slider from floating.

[0108] If an impact is input, the flexed portion 50 a of the FPC 50restrains the movement of the slider 4 as shown in FIG. 21. Thisprevents the slider 4 from rotating through a large angle due to theimpact. Thus, this embodiment provides effects similar to those of theseventh embodiment. Of course, by providing the roof as shown in thefirst to seventh embodiments, the rotation of the slider caused by theimpact can be reliably restrained. Although this embodiment connects themounting portion 824 and the flange portion 812 together using the FPC,similar effects can be obtained using an elastic material other than theFPC that is not very rigid and that can resist tensile force. The FPC ismounted on the mounting portion 824 and the flange portion 812 by usingan adhesive agent. The loop-like flexed portion 50 a, mounting portion824, and horizontal frame 825 shown in FIG. 21 are collectively referredto as a “flexure”. The FPC 50 may be integrally formed with the FPC (notshown) for writing or reading signals of the magnetic head.

[0109] This invention can control the contact angle between the sliderand the disc, thereby providing a magnetic-head supporting mechanismthat can reduce damage to the slider and disc caused by their contact inorder to provide high impact resistance, that exhibits high productivityusing the ultraviolet incidence window, adhesion condition observationwindow, and slider holding window, and that is suitable for a smallslider due to the decrease in the rigidity of the gimbal.

What is claimed is:
 1. A magnetic-disc apparatus for recording orreproducing information in which a slider loading a magnetic-head issupported on a magnetic disc, comprising: a supporting mechanism forsupporting said slider on said magnetic disc including a firstsupporting member mounting said slider and a second supporting memberconnected with said first supporting member; said first supportingmember including a mounting portion for mounting said slider, at leastone flexible finger portion provided at opposite sides of said mountingportion, and a connecting portion connected to said second supportingmember; said second supporting member including at a tip portion thereofa constricted portion extended to an end direction having a narrow widththan that between inner side edges of said two flexible finger portionsand a projecting portion projecting from said constricted portion to thedirection of width; and said projecting portion is overlapped with saidflexible finger portion in the outward direction of surface.
 2. Amagnetic-head supporting mechanism comprising a magnetic-head, a sliderhaving said magnetic-head, and a supporting mechanism for supportingsaid slider, a first supporting member mounted, comprising: amagnetic-head supporting mechanism including a first supporting memberfor mounting said slider and a second supporting member for connectingsaid first supporting member; said first supporting member including amounting portion for mounting said slider, at least one flexible fingerportion provided at opposite sides of said mounting portion, and aconnecting portion connected with said second supporting member; saidsecond supporting member including at a tip portion thereof aconstricted portion extended to an end direction having a narrow widththan that between inner side edges of said two flexible finger portionsand a projecting portion projecting from said constricted portion to thedirection of width; and said projecting portion is overlapped with saidflexible finger portion in the outward direction of surface.